Vehicle seat side air bag system

ABSTRACT

A side air bag restraint sub-assembly is disposed in a cavity in a vehicle seat. A reinforcement panel is secured to either the inflator bolts or the seat fame on one edge. The opposite edge of the reinforcement panel is sewn to a hem on one side of a tear seam.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for a vehicle seat mountedside air bag restraint.

2. Background Art

Air bag restraint systems for a vehicle seat are used to protect vehicleoccupants in the event of a side impact. Air bag restraint systems mustdeploy rapidly and predictably to be effective. Vehicle seats generallyinclude a rigid frame to which urethane foam pads are secured. The seatis typically enveloped within a cover made of vinyl, cloth or leather.An air bag module, including an air bag and an inflator system, issecured to the seat frame.

The softness and elasticity of covering materials and urethane foampadding present problems for air bag deployment. As the air bag deploys,it must be channeled so that the air bag deploys through an air bag tearseam in the seat cover material. The elasticity of the seat covermaterial allows the air bag to expand and cause the seat cover materialto bulge. This may increase air bag deployment time and result invariability in air bag deployment location. The resiliency and tendencyof the foam material to deform or fragment is another problem that mustbe solved.

One attempt to solve the above problems is disclosed in U.S. Pat. No.6,045,151 to Wu that employs a force concentrator that at leastpartially surrounds the folded air bag and concentrates or directs theforce of the inflating air bag to the intended deployment site. Theforce concentrator avoids application of air bag deployment forces onthe trim cover material to reduce the influence of the trim cover on airbag deployment. The force concentrator is an inelastic structure thatsurrounds or at least partially surrounds the air bag in an air bagmodule. This patent requires two panels to form the force concentrator.The use of two panels complicates assembly and may require that multiplepieces be joined together by seams. The Wu patent also discloses that asingle panel may work on only one side of the deployment seam, butstates that it must be verified that the addition of the concentratordoes not induce trim cover failure elsewhere.

Applicant's invention is directed to solving the above problems assummarized below.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a vehicle seatassembly is provided that comprises a frame and a pad formed of a shapedstructural foam material. The pad defines a pocket for receiving an airbag restraint sub-assembly that is assembled to the frame. The restraintsub-assembly has a housing in which an air bag and an inflator arereceived. The housing has a split line that functions as a stress riserin a wall of the housing. Upon inflation of the air bag by the inflator,the air bag is deployed through the split line. A trim cover isassembled to the pad and substantially encloses the frame, the pad, andthe restraint sub-assembly. The trim cover has a tear seam that openswhen the air bag is deployed. A reinforcement panel extends partiallyaround at least one side of the housing and between the housing and thetrim cover. The reinforcement panel is held in engagement with the frameby the inflator. The reinforcement panel is secured to a single side ofthe trim cover at the tear seam. The reinforcement panel resists elasticdeformation of the trim cover when the air bag is deployed and channelsthe air bag during deployment toward the tear seam.

According to other aspects of the invention, a reinforcement layer maybe secured to the pad adjacent to the pocket. The pocket has at leastone wall that extends from an outer surface of the pad and into thepocket adjacent to the restraint sub-assembly. The reinforcement paneloverlies the reinforcement layer. The air bag is channeled duringdeployment between the reinforcement panel and the reinforcement layertoward the tear seam. The reinforcement layer may be made of a fleecematerial that is molded in situ into the foam forming mold when the padis formed.

According to other aspects of the invention, the inflator may be securedto the frame by at least one bolt that is retained on the frame by anut. The reinforcement panel has at least one hole through which a thebolt of the inflator is received to secure the reinforcement panel tothe frame.

According to another aspect of the invention, the tear seam is formed bytwo doubled back edges of the trim cover material that are sewn togetherby a tear seam stitch. The reinforcement panel is sewn to one of thedoubled back edges of the trim cover.

According to other aspects of the invention, the restraint sub-assemblyis a side air bag module and the pocket is located on the outboard wallof the seat back portion of the vehicle seat. The reinforcement panelmay be a flexible, inelastic sheet of material that is less elastic thanthe trim cover. The reinforcement panel may be sewn to the trim cover.

According to another aspect of the present invention, a vehicle seatassembly is provided that comprises a frame and a pad formed of a shapedstructural foam material. The pad defines a pocket in which an air bagrestraint sub-assembly is placed. The air bag restraint sub-assembly hasa housing in which an air bag and an inflator are received and which isassembled to the frame. The housing has a split line that functions as astress riser. Upon inflation of the air bag by the inflator, the air bagis deployed through the housing of the split line. A trim cover isassembled to the pad and substantially encloses the frame, the pad, andthe restraint sub-assembly. The trim cover has a tear seam that openswhen the air bag is deployed. A reinforcement panel extends partiallyaround at least one side of the housing and between the housing and awall of the pocket. The reinforcement panel is held in engagement withthe frame by the inflator. The reinforcement panel is secured to thetrim cover at a location near the tear seam. The reinforcement panelprotects the pad when the air bag is deployed and channels the air bagduring deployment. The air bag is directed to deploy betweenreinforcement panel and the foam reinforcement toward the tear seam.

According to another aspect of the present invention, a vehicle seatassembly is provided that comprises a frame and a pad formed in theshape of a structural foam material that defines a pocket. An air bagrestraint sub-assembly is placed in the pocket and assembled to theframe. The restraint sub-assembly has a housing in which an air bag andan inflator are received. The housing has a split line through which theair bag is deployed upon inflation of the air bag by the inflator. Atrim cover is assembled to the pad that substantially encloses theframe, the pad, and the restraint sub-assembly. The trim cover has atear seam that opens when the air bag is deployed. A reinforcement panelextends partially around at least one side of the housing between thehousing and the trim cover. The reinforcement panel is held inengagement with the frame in a location that is spaced from therestraint sub-assembly. The reinforcement panel is secured to the trimcover at a location near the tear seam. The reinforcement panel resistselastic deformation of the trim cover when the air bag is deployed andchannels the air bag during deployment toward the tear seam.

Other aspects of the present invention will be better understood in viewof the attached drawings and following detailed description of severalembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary perspective view of the interior of a vehiclehaving a seat that is provided with a side air bag that is shown duringdeployment;

FIG. 2 is a fragmentary cross-sectional view of a vehicle seat having aside air bag module and a reinforcement panel made in accordance withone aspect of the present invention;

FIG. 3 is a fragmentary cross-sectional view of a tear seam to which areinforcement panel is shown according to one embodiment of theinvention;

FIG. 4 is a plan view of a reinforcement panel made according to thepresent invention;

FIG. 5 is a fragmentary cross-sectional view of a vehicle seat having aside air bag module made according to another embodiment of the presentinvention;

FIG. 6 is a fragmentary cross-sectional view of a vehicle seat having aside air bag module made according to another embodiment of the presentinvention; and

FIG. 7 is a fragmentary cross-sectional view of a tear seam to which areinforcement panel is sewn according to one embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring now to FIG. 1, a seat 10 for vehicle 12 is shown with a sideair bag 14 during deployment. The side air bag 14 is deployed in theevent of a side impact to the vehicle 12. The side air bag 14 isdeployed between the seat 10 and adjacent side of the vehicle 12 whichis in most instances a vehicle door.

Referring to FIG. 2, the seat 10 is shown to comprise a frame 16 towhich foam pads 18 are secured to form the seat structure. An air bagmodule 20 is received in the pocket 22 defined by adjacent foam pads 18.The air bag module 20 has a housing 24 in which the air bag 14 isreceived in a folded manner. An inflator 26 is a pyrotechnic devicedisposed within the housing 24 for rapidly inflating the air bag 14 inthe event of a side impact. As the air bag 14 is inflated by theinflator 22, it separates the housing 24 at a split line 28. A butterflyhinge 30 may be provided generally on the opposite side of the housing24 from the split line 28. The hinge 30 permits the housing to open in acontrolled manner.

The air bag module 20 is secured to the frame 16 by inflator bolts 32that are secured to the frame by a nut 34 or other type of fastener. Areinforcement panel 36 extends around the housing 24 generally from theinflator bolts 32 behind the housing and between a foam pad 18 and theair bag module 20 on one side. The panel 36 is preferably formed of aflexible but relatively inelastic fabric such as a nylon fabric or Tyvekor other material that is similar to the material used to form the airbag 14. The panel 36 includes holes 38 through which bolts 32 of theinflator 26 extend. The edge of the panel 36 through which the holes 38extend may be referred to as the anchoring edge 40 of the reinforcementpanel 36.

The seat 10 is enclosed in a cover 42 that covers the foam pads 18 andair bag module 20. The anchoring edge 40 is anchored between the air bagmodule 20 and the frame 16 as the seat 10 is assembled. The panel 36extends from the inflator bolts 32 at the anchoring edge 40 behind thehousing 22 and between the housing 24 and the foam pad 18. The panel 36further extends to a cover or fixed edge 44 that is turned back onitself and is sewn to the cover 42 and is more specifically describedwith reference to FIG. 3 below. A cover flap 46 extends over the outerside of the air bag module 20. The cover flap is designed to open whenthe air bag 14 is deployed. The cover flap 16 is intended to openinitially at a tear seam 48. The panel 36 is disposed between the module20 and the cover 42.

Referring to FIG. 3, tear seam 48 is shown in greater detail. Thereinforcement panel 36 is secured at a cover affixed reversely turnededge 44 to a panel hem 50. The cover flap 46 terminates at a flap hem52. The panel hem 50 including the reversely turned edge 44 and flap hem52 are secured together by means of tear stitches 54 that areconstructed to tear in preferential manner before cover 42 or cover flap46 will split under the pressure applied by the air bag 14 duringdeployment.

Referring to FIG. 4, the structure and shape of one embodiment of areinforcement panel 36 is shown prior to being assembled to the air bagmodule 20. The panel 36 has holes 38 near the anchoring edge 40 and thepanel hem 50, as shown adjacent the cover affixed edge 44. A trimcut-out 58 is shown in the lower corner of the panel. The trim cut-out58 provides clearance for cables or wiring to the air bag module.

Referring to FIG. 5, an alternative embodiment of the present inventionis shown in which a reinforcement panel 60 extends across the outer sideof the air bag module 20. The panel 60 has holes 62 near an anchoringedge 64. The holes 62 receive the inflator bolts 32 and is secured bynuts 34 as previously described with reference to FIG. 2. The panel 60extends between the air bag module 20 and the cover 66. A cover flap 68is defined where the cover 66 extends across the outer side of the airbag module 20. A cover flap 68 extends to a flap hem 70 that forms onepart of the tear seam 72. A cover hem 76 together with the flap hem 70are connected to form the tear seam 72.

A molded in situ foam reinforcement 78 is provided on a corner of thefoam pad 18 adjacent the air bag module 20. The reinforcement 78 may bea fleece fabric that is laid in the mold when the foam pad 18 is formed.

Referring to FIG. 6, yet another alternative embodiment of the inventionis shown wherein a panel 80 is sewn to a portion of a cover 82. Thepanel 80 is secured by a retainer clip 84 to a portion of the frame 16of the seat 10. The panel 80 extends between the cover 82 and the foampad 18. The panel 80 extends across the pocket 22 in which the air bagmodule 20 is received. The portion of the cover 82 extending across thepocket 22 is referred to as a cover flap 86. The panel 80 is preferablysewn to the cover 82 to reinforce the cover and prevent the cover frombulging when the air bag 14 deploys. The cover flap 86 terminates in aflap hem 90. The cover 82 terminates in cover hem 76 as previouslydescribed with reference to FIG. 5. The flap hem 90 and cover hem 76 aresecured together to form a tear seam 88.

Referring to FIG. 7, the tear seam 88 is shown in greater detail. Tearstitches 92 are secured between the flap hem 90 and cover hem 94. Thetear stitches 92 hold the cover flap 86 in position, as shown in FIG. 6,until the air bag 14 is deployed. Tear stitches 92 are intended to tearin a preferential manner so that the air bag 14 deploys through the tearseam 88 in a predictable manner.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. A vehicle seat assembly, comprising: a frame; a pad formed of ashaped foam polymer material, the pad defining a pocket; a air bagrestraint sub-assembly being placed in the pocket and assembled to theframe, the restraint sub-assembly having a housing in which an air bagand an inflator are received, the housing having a split line thatsplits a wall of the housing, wherein upon inflation of the air bag bythe inflator, the air bag is deployed through the split line; a trimcover assembled to the pad that substantially encloses the frame, thepad and the restraint sub-assembly, the trim cover having a tear seamthat opens when the air bag is deployed; a reinforcement panel extendspartially around at least one side of the housing and between thehousing and the trim cover, the reinforcement panel is held inengagement with the frame by the inflator, wherein the reinforcementpanel is secured to a single side of the trim cover at the tear seam,the reinforcement panel resisting elastic deformation of the trim coverwhen the air bag is deployed and channeling the air bag duringdeployment toward the tear seam.
 2. The vehicle seat assembly of claim 1further comprising a reinforcement layer secured to the pad adjacent tothe pocket, the pocket having at least one wall extending from an outersurface of the pad and into the pocket adjacent to the restraintsub-assembly, wherein the reinforcement panel overlies the reinforcementlayer and the air bag is channeled between the reinforcement panel andthe reinforcement layer during deployment toward the tear seam.
 3. Thevehicle seat assembly of claim 2 wherein the reinforcement layer is madeof a fleece material that is molded in situ into the pad.
 4. The vehicleseat assembly of claim 1 wherein the inflator is secured to the frame byat least one bolt and is retained on the frame by a nut, and wherein thereinforcement panel has at least one hole through which the bolt of theinflator is received to secure the reinforcement panel to the frame. 5.The vehicle seat assembly of claim 1 wherein the tear seam is formed bytwo doubled back edges of the trim cover material that are sewn togetherby a tear seam stitch, the reinforcement panel being sewn to one of thedoubled back edges of the trim cover.
 6. The vehicle seat assembly ofclaim 1 wherein the restraint subassembly is a side air bag module andthe pocket is located in an outboard wall of a seat back portion of thevehicle seat.
 7. The vehicle seat assembly of claim 1 wherein thereinforcement panel is a flexible, relatively inelastic sheet ofmaterial that is less elastic than the trim cover.
 8. The vehicle seatassembly of claim 1 wherein the reinforcement panel is sewn to the trimcover.
 9. A vehicle seat assembly, comprising: a frame; a pad formed ofa shaped foam polymer material, the pad defining a pocket; a air bagrestraint sub-assembly being placed in the pocket and assembled to theframe, the restraint sub-assembly having a housing in which an air bagand an inflator are received, the housing having a split line, whereinupon inflation of the air bag by the inflator, the air bag is deployedthrough the split line; a trim cover assembled to the pad thatsubstantially encloses the frame, the pad and the restraintsub-assembly, the trim cover having a tear seam that opens when the airbag is deployed; a reinforcement panel extends partially around at leastone side of the housing and between the housing and a wall of thepocket, the reinforcement panel being held in engagement with the frameby the inflator, wherein the reinforcement panel is secured to the trimcover at a location near the tear seam, the reinforcement panelprotecting the pad when the air bag is deployed and channeling the airbag during deployment across the reinforcement panel between the trimcover and the reinforcement panel toward the tear seam.
 10. The vehicleseat assembly of claim 9 wherein the inflator is secured to the frame byat least one bolt and is retained on the frame by a nut, and wherein thereinforcement panel has at least one hole through which the bolt of theinflator is received to secure the reinforcement panel to the frame. 11.The vehicle seat assembly of claim 9 wherein the tear seam is formed bytwo doubled back edges of the trim cover material that are sewn togetherby a tear seam stitch, the reinforcement panel being sewn to one of thedoubled back edges of the trim cover.
 12. The vehicle seat assembly ofclaim 9 wherein the restraint subassembly is a side air bag module andthe pocket is located in an outboard wall of a seat back portion of thevehicle seat.
 13. A vehicle seat assembly, comprising: a frame; a padformed of a shaped foam polymer material, the pad defining a pocket; aair bag restraint sub-assembly being placed in the pocket and assembledto the frame, the restraint sub-assembly having a housing in which anair bag and an inflator are received, the housing having a split line,wherein upon inflation of the air bag by the inflator, the air bag isdeployed through the split line; a trim cover assembled to the pad thatsubstantially encloses the frame, the pad and the restraintsub-assembly, the trim cover having a tear seam that opens when the airbag is deployed; a reinforcement panel extending partially around atleast one side of the housing and between the housing and the trimcover, the reinforcement panel being held in engagement with the frameat a location that is spaced from the restraint sub-assembly, whereinthe reinforcement panel is secured to the trim cover at a location nearthe tear seam, the reinforcement panel resisting elastic deformation ofthe trim cover when the air bag is deployed and channeling the air bagduring deployment toward the tear seam.
 14. The vehicle seat assembly ofclaim 13 wherein the reinforcement panel is sewn to the trim cover. 15.The vehicle seat assembly of claim 13 wherein the tear seam is formed bytwo doubled back edges of the trim cover material that are sewn togetherby a tear seam stitch, the reinforcement panel being sewn to one of thedoubled back edges of the trim cover.
 16. The vehicle seat assembly ofclaim 13 wherein the restraint subassembly is a side air bag module andthe pocket is located in an outboard wall of a seat back portion of thevehicle seat.